Preparation of unsaturated acid derivitives from corresponding saturated compounds by condensation with formaldehyde is known. For example, U.S. Pat. No. 3,701,798 disclosed the production of unsaturated acid derivatives through condensation with formaldehyde over catalysts containing rare earth oxides. U.S. Pat. No. 3,014,958 discloses an improvement for making unsaturated esters from formaldehyde and other esters wherein the feed contains more than 7% of the desired unsaturated ester. Catalysts used in this reference are phosphates and mixed oxides.
U.S. Pat. Nos. 3,933,888, 3,578,702 and 4,165,438 all disclose reactions using formaldehyde over various oxide catalysts such as vanadium-phosphorus, metals of the lanthanide series, or metals found in Groups IIA and Group IIIA of the Periodic Table.
It has now been discovered that derivatives of unsaturated acids can be obtained by the reaction of a saturated derivative with methanol and oxygen, over a suitable catalyst, thus eliminating the need for the use of formaldehyde. Since methanol can be made directly from carbon monoxide and hydrogen (synthesis gas), the invention significantly increases the economic incentive for the production of important monomers, such as methyl acrylate, from starting materials easily available from synthesis gas, e.g. methanol, acetic acid, methyl acetate, providing a viable alternative to processes based on petroleum hydrocarbons.